Absorbent articles for personal hygiene of the type indicated above are designed to absorb and contain body exudates, in particular large quantity of urine. These absorbent articles comprise several layers providing different functions, for example a wearer-facing topsheet, a garment-facing backsheet and in-between an absorbent core, among other layers. The function of the absorbent core is typically to absorb and retain the exudates for a prolonged amount of time, minimize re-wet to keep the wearer dry and avoid soiling of clothes or bed sheets.
The majority of currently marketed absorbent articles comprise as absorbent material a blend of comminuted wood pulp with superabsorbent polymers (SAP) in particulate form, also called absorbent gelling materials (AGM), see for example U.S. Pat. No. 5,151,092 (Buell). Cores having an absorbent material consisting essentially of SAP (so called “airfelt-free” cores) have also been proposed, see for example WO95/11652 (Tanzer), U.S. Pat. No. 6,790,798 (Suzuki), WO2008/155699 (Hundorf), or WO2012/052172 (Van Malderen). Absorbent cores with slits or grooves have also been proposed, typically to increase the fluid acquisition properties of the core or to act as a folding guide. WO2012/170778 (Rosati et al., see also WO2012/170779, WO2012/170781 and WO2012/170808) discloses absorbent structures that comprise superabsorbent polymers, optionally a cellulosic material, and at least a pair of substantially longitudinally extending channels.
The various components of an article are typically attached to another so that they stay in place before and during usage. Typical attachment means are gluing, heat and/or pressure bonding, ultrasonic bonding. The attachment means will be chosen by the manufacturer to balance costs of the equipments, cost of the glue material and performance required. Absorbent cores are typically attached to the backsheet by gluing, in particular by spraying the whole of the backsheet with a discontinuous glue layer before attaching both components together.
Alternative core-to-backsheet gluing patterns have been proposed. WO2012/170341A1 (Hippe) discloses a diaper having a reduced core-to-backsheet gluing pattern. In Hippe, the absorbent core is attached to the backsheet only in certain, limited areas. As a consequence, the formation of buckles and wrinkles in the backsheet, as well as the see-through of urine stains from the absorbent core through the backsheet can be reduced.
The present invention is directed to an improved core-to-backsheet gluing pattern, as will be further disclosed in the following specification.